1. Field of the Invention
The present invention relates to electrical circuit analysis, and more particularly to analysis of circuits, which involve transmission lines.
2. Description of the Related Art
Electrical circuits with transmission lines are analyzed using circuits and numerical techniques to ensure proper functioning of the circuits. Examples of such circuits include power distribution systems, which need to be analyzed for stability and other properties. The coupling and coupled signals between multiple lines is an important aspect of these power distribution systems.
Another example includes the analysis of circuits on microprocessor chips where a bus with hundreds of wires is to be analyzed to determine whether the wire to wire coupling is excessive.
Similar issues occur in electronic circuitry where noise coupled between transmission lines needs to be understood and minimized. Such issues occur in, e.g. instrumentation and/or computer circuitry in racks or cabinets.
The prior art uses multiple wire transmission line analysis techniques. Such techniques are described, for example, in the book by Clayton Paul, Analysis of Multiconductor Transmission Lines, Wiley, 1994, Chapter 5. Chapter 5 also includes the method of characteristics, which are used to make models for multi-conductor transmission lines. These techniques are suitable for the analysis of models with a few lines; however, the complexity increases rapidly as the number of lines increases.
Some simplified techniques have been used to approximate the solution for many transmission lines with neighbor-to-neighbor wire coupling only. These approaches are suitable where reduced accuracy is acceptable to gain speed.
The prior art is limited in the number of coupled lines or wired they can analyze simultaneously. The complexity of the coupling calculation is increases rapidly as the number of lines increases, and the accuracy of the results decreases with the increasing number of lines. Hence, the prior art is unable to handle a large number of lines due to excessive computation time and the results become questionable. Some prior art techniques ignore the couplings for more than two lines to speed up the process.
Some techniques are based on having only linear circuits to speed up the calculation process. These approaches are therefore unsuitable for handling even typical transmission line circuits, which include surrounding nonlinear drivers and receivers. Therefore, a need exists for an improved system and method for analyzing the coupling effects of transmission lines in electrical circuits to assure the proper function of the circuits. A further needed exists for a method and system for analyzing these effects timely and accurately.